Automatic train control



Patented July 5, 1932 UNirEo 'fsr rEs PATENT: OFFICE,

LoUIs -I-I. VON OHLSEN, on NEW nAvEm-coNnEoTIoUT, AssIGNon'To'rHn SAFETY GAR HEATING & LIGHTING COMPANY, A CORPORATION on NEW JERSEY AUTOMATIC TRAIN CONTROL Application filed February 4,1929. Serial No. 337,222.

This invention relates to train controlsystems and more particularly to equipment of this character wherein the movement. of a railway locomotive, car, or train, or other vehicle, is automatically controlled in accordance with the traffic condition of the track in advance of the train.

One of the objects of this invention is to provide a practical and effective railway signal and control system of simple construction and maximum reliability of operation. Another object is to providean efficient signal system of the character described for automatically indicating in a moving :vehicle the condition of the track in advance thereof and i for automatically controlling the movement of the vehicle in response to such condition. Another object is to provide a cab-signalling and-.train-control system of the above-meng0 tioned nature in which reliable communication may be established between devices along the track and cooperative devices upon the train or vehicle, inductively, and without the use of contact collectors or other sliding or rotating devices.- Another object'thereof is to provide for positive and reliable operationoof the signal and control-devices -irrespective of local disturbances, such as disturbances in the vehicle-carried circuit or V circuits, and, more particularly, irrespective of conditions efi'ecting fluctuations and changes in the train receiving circuit dueto fluctuations at orinthe sourceof electrical potential from which the circuit derives,'normally, its energizing current. Another object is to provide a simple, practical andreliable system-of the above nature wherein the vehicle-carried circuit or circuits or parts thereof may be safely supplied with energy 40 from sourcesthat, for example, supply also motive energy to electrical driving equipother object isgto provide a system in which in current changes in a relay system, determined by track conditions, serveto actuate train- I controlling or'signalling devices, which will be protected against actuation of said devices by changes in theenergizing current of the relay system brought about by causes other than the condition-of the track in ad- Vance. Other objects will be in partobvious V or' in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinationsof elements and arrangements of: parts which will be exemplifiedinthe structurefto be hereinafter described and the scope oftheapplication of which will be indicated in the following claims. I a o In the accompanying drawing, in which is shown one or more of various possible em bodiments of my invention, I V 7 Figure 1 shows diagrammatically a trainsignalling andcontrol system embodying a preferredformof my invention; and I Fig. 2 is. a similar diagrammatic sketch illustrating a modified form of my invention.

- Similar reference characters refer to similar parts throughout both views of the drawinov p iteferring'now to the drawing, it-is first to be noted that, for the sake of greater simplicity of illustration, certain parts of the system or apparatusare either diagrammati- I cally indicated or are omitted since they may take any suitable or appropriate form and since the details'thereof do not form any part of this invention. For example, there' is shown 'a relay 10 suitablyrelated to the roadbed and track circuit and actuated or controlled by suitable circuits, relays, or the like, in accordance with'the condition of the track inadvance of the moving vehicle, and the relay itself may,'in any suitable manner,

coact in effecting or controlling other or re:- lated circuits. Since the details of the circuits associated with the relay 10'form no part of this invention, such circuits are not illustrated. 1 1

'Associatedwiththe roadbed and preferably positioned adjacent or in between the rails isan electromagnetic'device generally switch member 14, by the relay 10. It will be understood that any suitable number of suitably spaced devices 11 are associated with the roadbed or track rails, in accordance, for example, with V the number. and

length of the blocks or rail sections. The remaining apparatus shown in Fig. 1' is carried by the vehicle and includesa device generally indicated at 15, adapted, as the vehicle moves along, to coact with the fixed device 11 associated with theroadbed. The device 15 includes an ironcore 16 providedwith certain energizing windings. These windings mayjbe energized fromany suitable source but, as illustrative of certain of the difiiculties which my invention overcomes, the windings are supplied with energy from agenerator-1?,mounted upon the vehicle with which is associated a storage battery 18 connected in circuit 1. The generator 17 is driven by 'a motor 19 which receives its energy from, for example, the. transmission circuit which supplies the vehicle with electric motive power. The generator 17 sup pliesenergy, preferably at much less voltage thanthe voltage of the transmission line, to any appropriate auxiliary devices, such as train control circuits, lamp circuits, signal lingdevices, etc, and to insure the supply of energy to such devices during periods when the generator 17 is not operating, the generatorl? maintains in substantially charged condition the storage battery 18. Any suitable automatic switch, indicated at 20, may be provided to automatically connect and "disconnect the generator and storage battery. In thepresent embodiment a lamp circuit is indicated at 2 in the drawing, and "a train signalling or control circuit is indicated bya legend. H I

' In certainpreferred forms of installation,

the motor 19 is constructed and designed to start, without starting transformers or res1stances,'1mmed1ately upon the line voltage 7 being impressed thereon, and-in any event the motor isfstarted and stopped in accordance with the supply. or interruption of power in the transmission line. The starting of the motor 19' under such circumstances oftentimes takes place frequently'and is so instantaneous tliatthe generator 17 builds up so rapidly" as to cause asubstantial surge in potential and currentfin its output. Vfhile V such surges not'be harmful with respect .to certain of the devices supplied with energy by the generator, yet it has been found that such fluctuation, surge, or the like, has been the cause of actuating the train signal and control circuitsirrespective of the con 'dition of the'track in advance. -A dominant aim of this invention is to prevent such imsuch a way as to be open-circuited should:

'gized by the current rent from the storage, battery, and at the proper actuation of the train signal and control circuits.

, Now, referring to Fig; 1 of the drawing for a more detailed understanding of the present control system, the electromagnetic device 15, which may be called a receiver, is carriedby some part of a locomotive or other .railway'vehicle in a suspended position over trafiic conditions in advance of the train be such as to establish the conditions under which the train control mechanism aboard the train'isto come into operation. 'The magnetic core 16 is provided with a pair of divergent pole pieces thrust downwardly toward the track inductor, the core being of a modified horse-shoe shape. On one leg of the core is a primary winding 21' connected to the storage battery by means ofcircuit 3, and on the other leg of said magnetic core is a secondary winding 22, which forms partof a circuit 4, connected in parallel with said primary circuit 3, as shown.- In series with said secondary winding 22 in said circuit 4 is a relay 23, which is normally enerin circuit 4 to'keep said circuit closed; I l

Before describing other features-shown in thedrawing, the normal-operation of the 2 devices already describedwill be explained. WVith the train runningfreely on an open signal, the primary coil 21 of the receiver receives a substantially constant direct oursame time the'relay 28 is energized by its connection tothe storage batteryto maintain the relay circuit 4 in closed condition.

Now, should thetrain pass over asection of track so as to bring the receiver 15in juxtaposition to one of said track inductors 11, and should the conditions obtaining in the trackin advance of the train besuch as to give a clear signah'the track relay shown in the drawing at 10 wouldmaintain closed the circuit through thewinding 13 upon said inductor. If, however, trafiic conditions should be such as to set a stop or other warning signal, the relay 10 would trip and opencircuit the winding 13, and, as the inductor ,125

passes under therpoles of the receiver, the air gap in the magnetic field of said receiver being suddenly shortened and the reluctance of the magnetic circuit reduced thereby, a sudden increase in the magnetic flux through the core16 would take place and induce a single cycle of A. C. in the secondary winding 22,.one1halif of which cycleis' in= opposition to the normal currentflowing through the relay circuit. This opposing current, be ing of sufficient strength to trip the relay 23, would setin operation or control the operation of the signalling or control devices maintained in the train control circuits. If, however, the winding upon the track inductor be close-circuited, the changing flux through said inductor as the latter passes under the vehicle-carried receiver will build up a current in said closedcircuit which will react uponsaid magnetic inductorto oppose storage battery 18, ifof sufficient scope, will also serve to cause current changes in the primary 210i the receiver 15' and induce in the secondary 22 thereof, waves of A. C. of whichparticular respective half-waves are opposed to the normal current in the relay circuit 4, which induced current may be of sufiicient strength to permit the tripping of e the relay 23 and produce activity in the train flowing through said circuits. 7

transformer connected in the circults Sand control circuits. This result is, of course, undesirable and to be avoided.

In Fig. 1, one way ofpreventing the accidentaland unintended actuation I of the train signal devices is disclosed A transformer is associated with the vehicle-carried circuits3- and 4 so as to have its primary winding-24 connected in series withthe primary coil 21 of the receiver,fwhile itssec ondary coil 25 is connected in series in the relay, circuit 4. Reslstances may. be 1ncluded in the two circuits, as indicated at' 26 and 27, to control and regulate the current With the .4, as described, should it'happen that the generator be suddenly brought lnto charging relation with the storage battery or that a heavy load be suddenly thrown upon the storage battery, causing substantially instantaneous and wide fluctuations in its output voltage, the resultant-rapid change in amperage of the current flowing through the primary winding 21 of ,thereceiver would, obviously, induce momentarily a current in the relay circuit 4 in opposition to the relay energizing currenttherein, tending'to trip the relay, but simultaneouslywith this efiect the primary coil 24 of the transformer, through which passes the same current that passes through the primaryof the receiver,

would be energized anda cur-rent inducedtin the secondary winding 25 of the transformer in a direction to opposethe currentari'si-ng in the receiver secondaryswinding122. :B'y properly proportioning Y the transformer coils 24 and 25,'the two currents inducedin.

therelayi'circuit may be made to neutralize one another andprevent the'potential change at the storage battery fronr tripping the relay 28. 1 ,1. 1 i

In Fig. 2 is disclosed another way-of con-' necting-the transformer in relation to circuits 3 and'4 so as toetlect the same results. In this case, the secondary 25.01? the trans former is connected as before, in series with the relay 23 and receiversecondary winding 22. But in this instance the primary 24 0f said transformer, and a resistance .26,are

connected acrossthebattery so as to be subjected directlyto voltagechanges acrossthe battery l8.-

change oft potential at the battery tending to cause current changes in the relay circuit to trip the relay will,'as .de-

scribed above, induce oppositely directed currents in the winding- 25 to neutralize or circuit, which tend to tripthe relay.

From. the foregoing, it will be seen that this invention is well adapted to a tainthe ends and objects thereof in a thoroughly practical and reliable manner; that tewmoving parts are employed which might get out of order and reduce the efficiency of thesystem; and that a train control system has j been devised whichmay safely be; used,With

'90 balance out the current changes in the relay power taken from aconvenient'source, even] though that source be'subject to suddenand' of its elecwide variations. in the potential trical output. 7 1

As many possible embodiments may be madeof the above inventionand as many changes might be made in the embodiment above setforth, it is to be understood that all matterrhereinbefore set forth orshown the accompanying drawing isfto be interand not. in a ll1]11i3ll1g preted as illustrative sense.

Iclaim: q 1 In an automatic train control system, in

combination, a. car movable along a track,

a receiver mounted upon said car. comprising an iron core and a primary and a secondarywcoil, a relay .adapted to control the operation of translating devices on said car,

a source of electrical potentiah'a receiver cir- V cuit connecting said primary coil with said source, a relay circuit connected to said source and including said secondary coil, and means associated with both of said circuits for neutralizing current effects produced in said relay circuit by sudden current changes in said primary coil due to potential fluctuations atthesource I 2. :In an automatic train control system,

in combination, a car movable along a track,

a receiver mounted upon said car comprising an iron core and a primary'and a secondary coil, a relay adapted to controlthe operation 'oftranslating devices on said car, a source --of electrical potential, a receivercircuit conn'e'ctin'g said primary coil with said source, a relay shunt' circuit connected to said source normally to hold said relay closed and in cluding said secondary coil, and inductively coupled means associated with both of said circuits for neutralizing current efi'ects produced in said relay circuit by sudden current changes in said'primary 0011 due to potential fluctuations at the source.

3. In an automatic tram control system, 1n

' combination, a source of potential carried on a vehicle, a vehicle-carried circuit having therein a relay and connected to said source both directly and inductively, and means for preventing actuation of said relay by induced "current in said circuit caused by. fluctuations at said source.

4. In an automatic train control system, in combination, a circuit'including a source of potential and a relay, a secondcircuit including said source and having relay coupled thereto, and means acting upon said first circuit to prevent current changes in said second circuit due to potential fluctuations at said source from actuating said relay.

'5. In an automatic train control system, in

combination, electro-responsive means including a vehicle carried source of potential and two inductively coupled c1rcu1ts connected in parallel tOSLlCl source, one of sa d circuits including a relay, means associated hicle and operatively responsive to the actuation of said relay, and means associated with both said circuits for neutralizing induced current effects in said relay circuit due to potential fluctuations at the source, I

6. In an automatic train control system, in combination, a source of. potential subject to fluctuations, two-train-carried inductively coupled circuits having associated therewith electro-responsive means energized by said source and responsive to track conditions, a relay associated with said circuits, and means for preventing fluctuations in said source of potential from actuating said relay comprising a transformeroperatively associated with j both of said circuits.

7. In an automatic train control system, in

combination, a source of potential carried on a vehicle, a pair of inductively coupled circuits connected in parallel to said source, a

. relay in one of said circuits, and means for preventing fluctuations in said source of potential from actuating said relay comprising a transformer having its secondary coil operatively associated with said relay-convice suspended over the track, a relay, a circuit including said source 'and'said electromagnetic device and said relay and controlling said vehicle-controlling device, a track inductor positioned to cut the field of said electromagnetic device as the vehicle passes, and inductive means associated with said relay-containing circuit for balancing out current efiect's induced by said electromagnetic device in said circuit through potential fluctuations at the source. V I

9. In an automatic train control system, in -combination,a storagebattery and a battery charging generator carried on a vehicle, a circuit including saidbattery, said generator and a switch adapted to open and close said'circuit, a train-controlling device in the vehicle,

a vehicle-carried electromagnetic device suspended'over the track, a relay, a circuit including said storage battery andsaid electromagnetic device and said relay and controlling said vehicle-controlling device, a track inductor positioned to cut the field of said electromagnetic device as the vehicle passes, and inductive means associated with saidrelay-containing circuit for balancing outcurrent effects induced by said electromagnetic device in said circuit through the opening and closing of said generator circuit.

10. In an automatic train control system, in combination, a vehicle-carriedstorage battery connected to be intermittently charged by a generator, a train-controlling device on the vehicle, a relay, a vehicle-carried electromagnetic device suspended over the track and comprising a primary-and a secondary coil,

a transformer having a primary and a secondary coil, a circuit including said battery and both of said primary coils, a circuit including said battery, said relay and both of said secondary coils and adapted to control said train-controlling device, and a track inductor positioned in the path of travel of the field of said electromagnetic device. I

'll. In an automatic train control system, in combination, a source of direct current carried by a vehicle and subject to sudden output voltage changes, a 'train controlling device on the vehicle, a relay controlling said train 'co'ntrolling device, a vehicle-carried electromagnetic device suspended over the track, a track inductor positioned in the path of travel of the field of said electromagnetic device and adapted to actuatesaid relay in response to trafic conditions, said electromagnetic device comprising a pair of inductively coupled coils, a circuit including one of said coils and said source, a circuit includ-.

circuit varies under the influence of voltage changes at the source, and a secondary coil connected in said second circuit and inductively coupled with said primary coil to supply a neutralizing current in said second circuit and prevent the actuation-of said relay through current effects caused therein by the inductive influence of current changes in'said first circuit upon said relay-containing circuit.

12. In an automatic train control'system, in combination, a source of suddenly variable direct current carried by a vehicle, a discontinuous magnetic core carried by said vehicle having a primary winding connected to said source and a secondary winding'connected to said source and having its magnetic circuit included in the magnetic circuit of said primary winding, a relay in the circuit of said secondary. winding, means positioned along the track in the path of travel of the magnetic field of said magnetic core and adapted under predetermined traffic conditions to induce current in said secondary winding to trip said relay, and inductive means electrically connected with both of said windings adapted to prevent sudden variations at saidsource from tripping said relay.

13. I11 an automatic train control system, in combinatioma source of suddenly variable direct current carried by a vehicle, a discontinuous magnetic core carried by saidvehicle having a primary winding connected to said source and a secondary winding con nected to said source and having its magnetic circuit included in the magnetic circuit of said primary winding, a relay in the circuit of said secondary winding, means positioned along the track in the path of travel of the magnetic field of said magnetic core and adapted under predetermined traific conditions to induce current in said secondary winding to trip said relay,,inductive means electrically connected with both of said windings adapted to prevent sudden variavtion at said source from tripping said re-' lay, said means comprising a coil connected in series relation with said primarywinding and said source, and a coil inductlvely coupled with said first coil and connected in series relation in said relay-containing circuit.

14. In an automatic train control system, in combination, a vehicle carrying a circuit having included therein a relay and electroresponsive means and a storage battery for locally energizing said relay and said electro-responsive means; means associated with,

the track along which said vehicle runs adapted to affect said electro-responsive means n accordance .with the conditions of the track a" source, of 1 potential :for charging said stor-t age battery; an automatic switch for connecting said source. to the battery when ,the

condition ,oftli'e former appropriate for charging ,the battery, and means for neutrall izing fluctuat ons 1n theenerg zing current in'said local circuit to' prevent actuation of.

the relay in response to-said fluctuations. v

15. 1 1 an'automatic'train control system, in combination, a vehicle arrying a storage battery having connectedthereto two circuits,

one ofsaidv circuits including a relay and a winding, the other of said circuits including a winding; a common core for said windngs, said core being positioned to be aiiected by means positioned alongthe track; a source of potential for charging said storage battery; and means causing a fluctuation inlocal energizing current in one circuit to neutralize the efiect of fluctuation in localenergi'zing current in the other circuit.

' 16. In an automatic train control system, in combination, a vehicle carrying a storage battery having connected thereto two cir-" cuits, one of said circuits including a relay and aiwinding, the otherof said circuits including a winding; a common core for said windings, said core being positioned to be afiected by means positioned along the track; a source of potential forcharging said storage battery; and inductively related wind- 7 mgs, one ineach of said circuits, for neutralizing in the latter the effects offiuctua;

tions in local energizing current. 7 a 17. In an automatic train control system, in

combination, a source of electrical energy sub ject to fluctuations, a magnetic core, a plul rality of windings about said core and connected to'said source, and a relay directly in terposed between one of said windings and said source: and inductively interposed between another of said source.

18. In an automatic train control system, in combination, a source of electrical energy subject tofiuctuations, a magnetic core, a plurality of windings about saidicore and conwindings and said nected to said source, arelay connectedto" saidwindings, an inductance interposed between one of said windings and said source, and a second inductance coupled with said first mentioned inductance interposed between another of said windings and said source whereby fluctuations of said source tending to operate sai-d relay are neutralized by saidcoupled inductances. a

19. In an automatic train control system including a vehicle and a track, in combination, a source of potential subject to fluctuations, a magnetic circuit mounted on said vehicle whose reluctance is made to change in accordance with the movement'of said vehicle overa cooperating control on said track,

1111621118 connected to said source operated by the'variation in the reluctance of said mag netic circuit, and inductively coupled means preventing variations in said source from actuating said first mentioned means but per- Initting free actuation due to the Variation in the reluctance of said magnetic circuit. 7

In testimony Whereofl I have signed my name to this specification this 18th day of i January,1929. c

I LOUIS HJVON O HLSEN. 

